So reproduction actually follows from the presence of dishes after the BP. Cups, bowls, jugs for drinks, all of this will be missing in any case, no matter how much We prepare. We often come across clay, and it’s not so difficult to sculpt from it, but it’s quite difficult to burn it.

Option one

Before firing, clay products must be dried at room temperature for 3–5 days, depending on the size. This evaporates most of the moisture in the clay. If the outside of the product is dry, but moisture remains inside, it may explode during firing. It also explodes when there are rocks in the modeling clay. After firing, the clay acquires new qualities - strength, rigidity, durability.

At home, when there is no muffle furnace, products can be fired on a regular electric or gas stove.

In this tutorial we will use an electric stove.

Using a small frying pan and a cast iron pot for firing your clay products. Pour fine sand into the bottom of the frying pan to gradually heat it up. We place the figurine on the sand and cover it with a pot.

The heating temperature must be increased gradually. First, turn on the minimum heat for 30 minutes, then raise the temperature to maximum for 5–6 hours. Before removing the clay figurine, you must wait for it to cool completely.

Second option

At my dacha I had the opportunity to use the most primitive and unpredictable method - firing at the stake (this is not recommended in specialized literature, since this wild method can ruin your work). I decided to conduct an experiment. I laid out a small double-sided brickwork (it’s better if you can lay it out on four sides and leave room for a closed hole to make it easier to light a fire). The height of my masonry was 4 bricks, but this is not so important, the main thing is that then it would be possible to cover this masonry on top along with the product and leave it until the fire completely extinguishes and cools down. And you need to place the product so that the coals do not come into contact with it. To protect products from contamination and mechanical damage when fired in an open fire (on a fire and in a kiln), they can be placed in special capsules. The simplest capsules are made from cans, punching several small holes in them so that the products do not darken during firing.

First, light a fire (only birch logs are suitable), then clear a central place for the dried (this is a prerequisite for any firing!) product, and place it on a brick base or in a capsule on the ground so that there is a high temperature on all sides when the fire will flare up (this is necessary for uniform firing). Control of a more or less gradual increase in temperature will be required. I heated the product in an electric oven and, using a warm mitten, transferred it to a warm place near the fire (to avoid temperature changes). If you place it cold, then don’t let the fire come close at the beginning of firing, let it warm up, then watch the temperature. When we cook kebabs, we protect the meat from the fire, but you don’t have to protect the clay, just let it gradually get closer to it, so that the product does not burst due to a sharp increase in temperature, and when the fire stops whipping up, you can cover the top with something fireproof (lid from a barbecue, a piece of old metal sheet, etc.). I had a rusty piece of roofing on hand, which we use to blow on the fire when starting it. Then you can leave it to burn out uncontrollably and cool. The entire burning process takes at least three hours, and it will also take a slow cooling time, so in the evening or running, nothing will happen (you need to watch the firing). The product must be heated on all sides, otherwise you will hear clicks from explosions (it is better not to sit children nearby, in case a fragment will fly off), this practice is possible with this method. Successful results are obtained with small-sized products, whistles, but you still have no guarantee that you will save each of them.

Firing ceramics is divided into several stages depending on the heating temperature of the kiln.

HEAT

20 — 100
At the initial stage of heating, moisture is removed from the clay or other ceramic mass. Warming up should be slow. The most important thing is to maintain uniform heating. The heating rate is determined by the thickness of the walls of the product: the thicker the walls, the slower the heating should be.

100 — 200
At this stage, the process of removing moisture from the mass continues. It is important to remember that the temperature readings on the device are usually higher than the temperature of the product itself, especially if the product is thick or if the product is located on a thick stand that absorbs some of the heat. The shrinkage of the glazes also begins. During this heating period, as water is still being evaporated from the piece, the glaze coating is at risk of cracking or fragmented chipping. Heating must be uniform, as volatile organic compounds are released from chandelier coatings.

200 — 400
Organic compounds burn out in this range. A good air flow is especially necessary if the content of organic matter in the mass is high (decals, chandeliers, binders of overglaze paints and mastics).

550 — 600
When the furnace is heated to these temperatures, a phase transformation of quartz occurs, which is characterized by abrupt changes in the internal energy of the substance and, accordingly, its density, as well as heat capacity, compressibility and coefficient of thermal expansion. Therefore, during the cooling stage, the ceramics may crack (so-called “cold” crack).

400 — 900
In this gap, chemically bound water is released from the clay, and a number of minerals contained in it also decompose. Chloride and nitrate salts also decompose.

600 — 800
At these temperatures, melting of overglaze coatings, as well as low-melting fluxes (lead and others), begins.

750 — 800
In this interval, which is sometimes called the third decorative firing, the burning of sulfides occurs, as well as the softening of the glaze surface and the diffusion of paints, gold, etc.

850 — 950
In this interval, the chalk and/or dolomite contained in the ceramic mass decomposes. The interaction of a component of the ceramic mass - silica - with calcium and magnesium carbonate begins. These processes are accompanied by the release of carbon dioxide.
At this stage, all transformations of clay substances also end: the strength of the shard is ensured by sintering of the smallest particles.
By the end of the majolica glaze interval, as a rule, they are completely melted.

1000 -1100
At this stage, compaction and deformation of the shard occurs, and the feldspars begin to soften.
The liquid phase appears as a result of the intense interaction of silica and lime.
Sulfates also decompose intensively, which is accompanied by the release of sulfur dioxide.
Melting of nepheline-syenite occurs.

1200 -1250
In this range, earthenware and white-burning ceramic masses are sintered.
Silica and kaolinite dissolve in the feldspar melt.

1280 — 1350
In this temperature range, mullite needles penetrate the porcelain mass, which, after leaving the firing, is the basis for high strength and heat resistance. The process is called mullite formation.
Fine quartz is also transformed into cristobalite.

1200 — 1420
This interval is used for firing porcelain. At such high temperatures, diffusion occurs very quickly. Also at such temperatures, if the necessary redox firing conditions are provided, the processes of reduction of red iron oxides into more noble blue ones occur.

COOLING

1420 — 1000
The mass and glazes are in a fairly plastic state, so the product is cooled as quickly as the technical characteristics of the furnace allow.
If you are using glazes that are prone to crystallization, then slow cooling or holding for up to 10 hours in this interval will usually lead to crystal growth.

1000 — 700
Here the oxidation of manganese, lower oxides of copper and other metals, if any are contained in the composition, into higher ones begins.
Lack of oxygen in the furnace can give the surface of the product metallization. If restoration is planned, then it must be done within this interval. The reducing environment must be maintained at least to 250-300C, and preferably to almost room temperature.

900 — 750
The mass (shard) and glaze have become brittle and are cooling as a single whole. If the CTEs are not agreed upon, then rebound of the glaze, cracks, and even damage to the product are possible.

600 — 550
At this stage, a reverse phase transformation of quartz occurs with a sharp volume change. Going through this interval too quickly can cause a “cold” crackling sound.

300 — 200
In this interval, the phase transformation of cristoballite occurs. It was formed at a temperature of 1250 - 1300, if the mass contained very finely dispersed silica. The oven door does not need to be opened quickly.

250 — 100
Cooling continues in this interval. In the thick parts of the products, as well as in the depths of the furnace, the temperature is much higher than in the thin parts and as indicated by the measuring element. The products must be allowed to cool evenly.

Clay products are a very exciting and interesting process that allows you to unleash your imagination and talent. If you want your clay figures to not lose their shape for a long time, you need to dry them, and then fire the clay at home, following a certain technology. After all, the long service life of your products will constantly please you. All your figures are unique - they only resemble themselves.

Material composition

Clay can have different compositions. It directly affects the firing technology. Natural clay contains an admixture of sand. The following pattern stands out: the less sand is included in the clay, the lower the temperature should be when firing the products. There are situations when, when using powdered purchased clay, it boils at 750 degrees and then dries out. As a result, the product resembles a porous sponge. In this case, the clay figurine is usually destroyed.

The clay composition must be free of air and stones. Never use heterogeneous materials because an explosion may occur. Because the composition will include materials that have different densities, and they will each expand in their own way when the temperature changes.

Natural clay is a material of natural origin and is often not subject to additional processing. In nature, you can find clay of various colors, which depends on the presence or absence of certain elements. For example, clay acquires its red color due to the presence of large amounts of iron. And if there are small quantities of iron and titanium oxides in raw clay, then the white color of the material remains even after firing.

Preparing material for firing

Before firing the clay, it must be dried. You will spend about a week on this process, depending on the size of the product. It is recommended to dry it in places where there are no heating devices nearby and where direct rays of the sun do not reach. The best option is room temperature and a dark, dry place. This is where the product dries evenly.

If the clay is dried unevenly, cracks or chips may form on the product. If it is not dried enough, the products may have defects after firing. But it is impossible to dry out the clay.

When the product has dried, it must be carefully inspected to see if there are any cracks on it. If they are present, they can be masked with liquid clay, but this does not guarantee that the product will not lose its shape during firing. It is best to prevent cracks from appearing. This can be achieved, you just need to properly prepare the clay and sculpt the product with high quality.

The final stage of preparation is polishing the clay figurine. During sanding, fingerprints and bumps are removed, and as a result, the products acquire a beautiful and well-groomed appearance. Sanding is carried out using sandpaper.
Another important factor is the quality of the sculpting. Make sure that there are no air bubbles in the figure while sculpting. When the temperature rises, the air expands and seeks a way out, as a result of which the product will burst. When you seal cracks or fasten pieces together, do it very carefully so that air capsules cannot form.

Rules for firing at home

You can fire clay at home. First you need to dry the product and then fire it in the oven. In this case, you need to gradually increase the temperature over two hours to 200 degrees. Clay figurines can be placed in a frying pan or cast iron pot. It should be taken into account that full firing in the oven is impossible, because the temperature is insufficient, it cannot harden it, but only dry it.

How to determine if a product is ready?

Very easy based on color, weight and sound. If the color of the baked clay is black, then the figurine is overheated. If the color has not changed, then the product has not been fired enough. Fired colored clay should be red in color.

Clay firing technology

Clay kiln

The best option for firing clay is this is a muffle furnace . The temperature in this oven can be adjusted. It should be remembered that such a stove is very expensive and not everyone can afford to buy it. But there is no need to be upset, because it can be replaced with other good devices, for example, firing clay in the oven. Start firing the clay at 200° for 2 hours. Then, over the course of 6 hours, gradually raise the temperature to 1000°. This temperature regime allows you to protect the clay product from stains and help maintain a uniform structure.

Clay firing can also be done in barbecue or brick oven . These species are a closed space characterized by a stable temperature. It is needed so that the clay product heats up evenly, and various defects do not form on it, such as spreading of the surface. The product that is being fired must be left until the fuel has completely burned out and the firebox has cooled down. The product should be in the oven for approximately 4 hours.

Firing a clay product over a fire is a very affordable option. It is used for firing small items. So, take the clay product and place it in a tin vessel, which you have previously heated and made holes in the sides. In most cases, the vessel is an ordinary tin can. Fire the product for about 8 hours, no less.

Fire clay impossible in the microwave . Such an oven can only remove moisture. Clay products, after you have air dried them, place them in the microwave for 3 minutes. This is done to make their condition better.

Temperature

The main rule in firing clay products is that you need to gradually raise the firing temperature and then gradually lower it, giving the product time to cool. At first (first 2 hours) the temperature should be no more than 400°. The firing temperature can fluctuate in the range of 200-1000° during firing. If the temperature is lower, the firing will be insufficient and the figurine will not have the desired properties. If the temperature is very high, then the figurine may collapse.

Duration

This process can last from eight hours to several days. This depends on the size of the product and the firing technology. If the figure is small, then this can be done in the shortest possible time.

This is important to know!

• Once the clay is fired, the product can no longer be changed.
• You can do the firing more than once, while gradually raising the temperature to achieve the optimal result and gain experience.
• Once you have completed the main firing, you can apply a special coating to the figurine and then fire it again. This coating will melt and form a glaze.
• When dried and fired, the figurines may become deformed and decrease in size. That is why, when creating a product, you should take into account the composition of the clay and its future purpose.
• If the clay contains a lot of sand, the product will be less subject to compression.
• Also remember that during firing organic compounds burn out, which in turn leads to unpleasant odors. Therefore, it is required that the room be ventilated.

Clay products are actively used by people in modern life, especially for dishes and various items for interior decoration. Knowing what is the optimal temperature for firing clay and what tools are needed for this, you will be able to create real masterpieces with your own hands. The following describes how to fire clay at home. The first step is to prepare the material. After all, the clay must be dried thoroughly. The drying time depends on the size of the product created by the master. But usually it is about 7 days. You should not try to reduce the number of days by using the sun or heating devices. The clay should be dried in a dry, dark room at room temperature. This will ensure it dries evenly. Otherwise, unsightly cracks may appear on the material. After firing they will turn into silver defects.

After the drying period has expired, you will need to carefully inspect the product and make sure that there are no cracks or other similar surface changes. Some craftsmen try to disguise the defects that appear with the help of liquid clay, but during the firing process such a clay figure often loses its shape and restoration becomes impossible. Poor-quality modeling also leads to the same result, when air bubbles are mixed with the clay. During firing, the temperature rises greatly, and the air begins to seek a way out. As a result, the pot or any other item may simply burst. Therefore, it is worth holding all the clay particles together in such a way as to completely eliminate the possibility of the formation of air capsules between them. Lastly, before firing, the product is sanded with sandpaper. This allows you to remove pits, protrusions, hand marks and other imperfections from its surface.

Of course, a muffle furnace is best suited for the process under discussion. It is easy to install a clay product into it, after which you can start firing. The main advantage of such a stove is the ability to regulate the temperature. But at the same time, it is quite expensive and not every master can afford it. Therefore, you can use the most ordinary oven instead. For high-quality firing, you will first need to leave the clay product at a temperature of 200 degrees for 2 hours, and then continue to process it for 6-7 hours, gradually raising the temperature. As a result, it should reach 1000 degrees. Thanks to this, stains will not appear on the clay product and its structure will remain uniform. A good alternative would be a barbecue or a brick oven. The clay object should remain in the latter for approximately 4-5 hours.

A very affordable option is firing clay using a fire. True, it is suitable exclusively for processing miniature objects. It is important to remember that clay cannot simply be placed on a fire and left there to fire. You will first need to hide it in a tin container. For example, you can take the most ordinary tin can. In this case, the firing time will need to be increased to approximately 8-9 hours. The main thing is that the fire does not go out all this time and that it maintains a high temperature. It is very difficult to fire clay directly in the apartment. In some instructions you can find tips that this can be done in the microwave in just a couple of minutes. In fact, the microwave only allows you to consolidate the drying result immediately before firing. To do this, the product is placed in it for 3 minutes at full power.

But you can try firing small clay products using a frying pan and a cast iron pot. It is very important not to forget to pour fine sand into the bottom of the pan. This will ensure gradual, high-quality heating of the structure. The selected figurine is placed on the sand and covered with a pot and cast iron. First, the minimum heating temperature is set for approximately 30 minutes, then it gradually increases to the maximum. In this state, the clay product remains in the frying pan under the pot for 6-7 hours. This design and time will be sufficient for high-quality, full-fledged firing. The main thing is to act as carefully as possible, especially when checking the condition of the figurine in the frying pan, since the clay pot will be very hot and it will be easy to seriously damage your hands or other parts of the body.

1. Where do you get clay?
- Clay for modeling can be bought in stores that sell creative materials. Clay is also sold on the Internet; you can use a search engine to find such stores. As for the Moscow region, clay is available in Gzhel and it costs less there. In Moscow, for example, this is a store for ceramists, Horses, on Ul. Verkhnyaya Maslovka, 18 or Vorontsovsky plant, St. Architect Vlasov, 57

2. Is it possible to dig up clay from a quarry and use it for modeling?
- It’s possible, but to do this, the clay must first be cleaned of impurities (for example, small pebbles). To do this, the clay is diluted in water to the consistency of sour cream and filtered through a fine-fine sieve (coffee filters work well). Then the clay is poured onto gypsum slabs (you can make them yourself or buy them in specialized stores, such as Horse) and it is “pulled” - the gypsum absorbs excess moisture, and the dried clay is easily removed from the slabs and can be used for modeling. If there are no gypsum boards, then you need to let the clay settle and drain excess water from above. Then you need to wait until the clay dries to the point where you can sculpt from it. With gypsum boards, clay dries much faster.

3. Is it possible to fire clay in the oven or microwave? or do I need a special oven?
- It’s impossible, because firing requires a temperature of about 1000 degrees. The oven only heats up to 250. A microwave won’t work either, you need a special oven.

4. Is it possible to install a kiln at home?
- Maybe a small one. This could be a laboratory muffle furnace made at a factory. Or assembled by a stove maker according to your individual dimensions. Potters usually know good stove makers and can be recommended by craftsmen. But we must also take into account that it is not useful to breathe in the fumes that are released during firing and it is still better to use a separate room for the kiln, preferably with an exhaust hood.

5. Is it possible to work at home on a pottery wheel?
- You can, if you don’t feel sorry for the apartment, or rather the renovations in it. Because the splashes will fly from the circle in different directions, no matter how carefully you try to twist it. Although many craftsmen keep a circle at home, having allocated a special corner for it or protecting the apartment with oilcloths and curtains.

6. Is it possible to make a product on a pottery wheel the first time?
- Completely on your own - unlikely. But with the help of a master, you will definitely make your first work that you can use. It may be crooked, but this will only give it additional charm.

7. Is it possible to make a lid for a teapot to replace the broken one?
It is possible, but quite problematic, since clay shrinks by 8-10% during drying, which means it will be difficult to determine the size. It's faster and easier to make a new kettle.

8. Is it possible to immediately fire a freshly molded product?
No, the product must first be completely dry. Under natural conditions, this happens for 5-7 or more days (up to a month for large products) and only then can it be fired. If you put a raw product in the oven it will explode

9. What should you do if your cat’s ears fall off after drying?
Depends on what clay you made it from. Some clays allow you to slightly wet the place where you need to glue the ears and the ears themselves and try to apply them. If this number does not work with your clay, you can fire it and after firing, glue it either to glaze or to silicate glue, if you do not plan to fire with glaze. And in the future, even when sculpting, try to carefully glue the parts onto water or onto a slip - this is what liquid clay is called.

10. Is it possible to repair a crack in a ceramic product?
Depends on the crack. If this is a micro crack, then it is likely that it will disappear under a layer of glaze, but it may, on the contrary, become even larger. This will become clear after firing with glaze. If you do not plan to glaze the product, but want to paint it with acrylic paints, you can fill the crack with plaster and then paint it with acrylic. Plaster can be used to seal a crack of any size. Products coated with acrylic paints cannot be used for food purposes.

11. Is it possible to pour water into ceramic products (vases, mugs) that are not covered with glaze?
Ceramics is a porous material and will allow water to pass through without additional treatment. That is why it is covered with glaze. Also, ceramics can be boiled in milk at a temperature of approximately 350-380 degrees, the milk burns out and clogs the pores, so the product stops letting water through and acquires a dark shade. This method was invented even before the invention of glazes, it is called milking.